001 /* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2008, by Object Refinery Limited and Contributors.
006 *
007 * Project Info: http://www.jfree.org/jfreechart/index.html
008 *
009 * This library is free software; you can redistribute it and/or modify it
010 * under the terms of the GNU Lesser General Public License as published by
011 * the Free Software Foundation; either version 2.1 of the License, or
012 * (at your option) any later version.
013 *
014 * This library is distributed in the hope that it will be useful, but
015 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
016 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
017 * License for more details.
018 *
019 * You should have received a copy of the GNU Lesser General Public
020 * License along with this library; if not, write to the Free Software
021 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
022 * USA.
023 *
024 * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
025 * in the United States and other countries.]
026 *
027 * ---------------
028 * XYDataItem.java
029 * ---------------
030 * (C) Copyright 2003-2008, by Object Refinery Limited.
031 *
032 * Original Author: David Gilbert (for Object Refinery Limited);
033 * Contributor(s): -;
034 *
035 * Changes
036 * -------
037 * 05-Aug-2003 : Renamed XYDataPair --> XYDataItem (DG);
038 * 03-Feb-2004 : Fixed bug in equals() method (DG);
039 * 21-Feb-2005 : Added setY(double) method (DG);
040 * ------------- JFREECHART 1.0.x ---------------------------------------------
041 * 30-Nov-2007 : Implemented getXValue() and getYValue(), plus toString() for
042 * debugging use (DG);
043 *
044 */
045
046 package org.jfree.data.xy;
047
048 import java.io.Serializable;
049
050 import org.jfree.util.ObjectUtilities;
051
052 /**
053 * Represents one (x, y) data item for an {@link XYSeries}.
054 */
055 public class XYDataItem implements Cloneable, Comparable, Serializable {
056
057 /** For serialization. */
058 private static final long serialVersionUID = 2751513470325494890L;
059
060 /** The x-value (<code>null</code> not permitted). */
061 private Number x;
062
063 /** The y-value. */
064 private Number y;
065
066 /**
067 * Constructs a new data item.
068 *
069 * @param x the x-value (<code>null</code> NOT permitted).
070 * @param y the y-value (<code>null</code> permitted).
071 */
072 public XYDataItem(Number x, Number y) {
073 if (x == null) {
074 throw new IllegalArgumentException("Null 'x' argument.");
075 }
076 this.x = x;
077 this.y = y;
078 }
079
080 /**
081 * Constructs a new data item.
082 *
083 * @param x the x-value.
084 * @param y the y-value.
085 */
086 public XYDataItem(double x, double y) {
087 this(new Double(x), new Double(y));
088 }
089
090 /**
091 * Returns the x-value.
092 *
093 * @return The x-value (never <code>null</code>).
094 */
095 public Number getX() {
096 return this.x;
097 }
098
099 /**
100 * Returns the x-value as a double primitive.
101 *
102 * @return The x-value.
103 *
104 * @see #getX()
105 * @see #getYValue()
106 *
107 * @since 1.0.9
108 */
109 public double getXValue() {
110 // this.x is not allowed to be null...
111 return this.x.doubleValue();
112 }
113
114 /**
115 * Returns the y-value.
116 *
117 * @return The y-value (possibly <code>null</code>).
118 */
119 public Number getY() {
120 return this.y;
121 }
122
123 /**
124 * Returns the y-value as a double primitive.
125 *
126 * @return The y-value.
127 *
128 * @see #getY()
129 * @see #getXValue()
130 *
131 * @since 1.0.9
132 */
133 public double getYValue() {
134 double result = Double.NaN;
135 if (this.y != null) {
136 result = this.y.doubleValue();
137 }
138 return result;
139 }
140
141 /**
142 * Sets the y-value for this data item. Note that there is no
143 * corresponding method to change the x-value.
144 *
145 * @param y the new y-value.
146 */
147 public void setY(double y) {
148 setY(new Double(y));
149 }
150
151 /**
152 * Sets the y-value for this data item. Note that there is no
153 * corresponding method to change the x-value.
154 *
155 * @param y the new y-value (<code>null</code> permitted).
156 */
157 public void setY(Number y) {
158 this.y = y;
159 }
160
161 /**
162 * Returns an integer indicating the order of this object relative to
163 * another object.
164 * <P>
165 * For the order we consider only the x-value:
166 * negative == "less-than", zero == "equal", positive == "greater-than".
167 *
168 * @param o1 the object being compared to.
169 *
170 * @return An integer indicating the order of this data pair object
171 * relative to another object.
172 */
173 public int compareTo(Object o1) {
174
175 int result;
176
177 // CASE 1 : Comparing to another TimeSeriesDataPair object
178 // -------------------------------------------------------
179 if (o1 instanceof XYDataItem) {
180 XYDataItem dataItem = (XYDataItem) o1;
181 double compare = this.x.doubleValue()
182 - dataItem.getX().doubleValue();
183 if (compare > 0.0) {
184 result = 1;
185 }
186 else {
187 if (compare < 0.0) {
188 result = -1;
189 }
190 else {
191 result = 0;
192 }
193 }
194 }
195
196 // CASE 2 : Comparing to a general object
197 // ---------------------------------------------
198 else {
199 // consider time periods to be ordered after general objects
200 result = 1;
201 }
202
203 return result;
204
205 }
206
207 /**
208 * Returns a clone of this object.
209 *
210 * @return A clone.
211 *
212 * @throws CloneNotSupportedException not thrown by this class, but
213 * subclasses may differ.
214 */
215 public Object clone() throws CloneNotSupportedException {
216 return super.clone();
217 }
218
219 /**
220 * Tests if this object is equal to another.
221 *
222 * @param obj the object to test against for equality (<code>null</code>
223 * permitted).
224 *
225 * @return A boolean.
226 */
227 public boolean equals(Object obj) {
228 if (obj == this) {
229 return true;
230 }
231 if (!(obj instanceof XYDataItem)) {
232 return false;
233 }
234 XYDataItem that = (XYDataItem) obj;
235 if (!this.x.equals(that.x)) {
236 return false;
237 }
238 if (!ObjectUtilities.equal(this.y, that.y)) {
239 return false;
240 }
241 return true;
242 }
243
244 /**
245 * Returns a hash code.
246 *
247 * @return A hash code.
248 */
249 public int hashCode() {
250 int result;
251 result = this.x.hashCode();
252 result = 29 * result + (this.y != null ? this.y.hashCode() : 0);
253 return result;
254 }
255
256 /**
257 * Returns a string representing this instance, primarily for debugging
258 * use.
259 *
260 * @return A string.
261 */
262 public String toString() {
263 return "[" + getXValue() + ", " + getYValue() + "]";
264 }
265
266 }